Theresa M Barrett

US Patent:

20040154423, Aug 12, 2004

Filed:

Feb 7, 2003

Appl. No.:

10/360290

Inventors:

Faydor Litvin - Skokie IL, US
Xiangshun Zhao - Auburn Hills MI, US
John Sofia - Birmingham MI, US
Theresa Barrett - Leonard MI, US

International Classification:

F16H055/08

US Classification:

074/462000

Abstract:

The present invention provides an advanced geometry for skew and straight bevel gears having a localized and more stable bearing contact produced by forging. The localization of bearing contact is achieved by substitution of flat tooth surfaces with parabolic tooth surfaces. This is accomplished by either modifying line-contact directly or by using a generating parabolic cylinder during generation of the tooth surfaces. The actual contact area is spread over an ellipse centered around an instantaneous theoretical point of contact at the apex of the parabolic tooth surface. This localized bearing contact reduces the shift of the bearing due to assembly and manufacturing errors, thereby providing a more durable and quieter gear. Furthermore, the geometry of the gear enables creation of dies from which the gear may be forged. Transmission errors are modeled using a pre-designed parabolic function that coincides with the parabolic tooth surface design of the present invention.